A conventional combustible gas turbine engine includes a compressor, a combustor, and a turbine. The compressor compresses ambient air. The combustor combines the compressed air with a fuel and ignites the mixture creating combustion products defining a working gas. The working gas travels to the turbine. Within the turbine are a series of rows of stationary vanes and rotating blades. Each pair of rows of vanes and blades is called a stage. Typically, there are four stages in a turbine. The rotating blades are coupled to a shaft. As the working gas expands through the turbine, the working gas causes the blades, and therefore the shaft, to rotate.
A coolant, such as air, may flow out from orifices in the first row of vanes to cool the vanes. That coolant reduces the temperature of the working gas by dilution as the working gas passes through the first row of vanes in the turbine assembly. This decrease in temperature in the working gas prior to impinging upon the first row of blades decreases the efficiency of the gas turbine engine. Further, the elements comprising the first row of vanes are costly.